Soil Selection Guide

This guide will help you select the appropriate soil testing equipment for your specific needs. Accurate soil testing is crucial for geotechnical investigations, foundation design, earthwork construction, and environmental studies. Here’s a breakdown of common soil properties and the equipment used to test them:

Index Properties:

• Moisture Content:

  • Test: Oven Drying Method
  • Equipment: Drying Oven, Balance, Moisture Cans
  • Considerations: Oven temperature control (105-110°C), balance accuracy, standards compliance (ASTM D2216, AASHTO T265).

• Particle Size Distribution (Gradation):

  • Test: Sieve Analysis (for coarse-grained soils), Hydrometer Analysis (for fine-grained soils)
  • Equipment: Sieves (various sizes), Sieve Shaker, Hydrometer, Sedimentation Cylinder, Stirring Apparatus, Drying Oven, Balance
  • Considerations: Sieve sizes (mesh openings), shaker type, hydrometer type, standards compliance (ASTM D422, AASHTO T88).

• Atterberg Limits:

  • Tests: Liquid Limit, Plastic Limit, Shrinkage Limit
  • Equipment: Liquid Limit Device (Casagrande or Fall Cone), Plastic Limit Rolling Device, Shrinkage Limit Mold, Drying Oven, Balance
  • Considerations: Liquid limit device type, groove tool dimensions, standards compliance (ASTM D4318, AASHTO T89, T90).

• Specific Gravity:

  • Test: Specific Gravity Test
  • Equipment: Pycnometer, Drying Oven, Balance
  • Considerations: Pycnometer size, temperature control, standards compliance (ASTM D854).

 

Engineering Properties:

• Shear Strength:

  • Tests: Direct Shear Test, Triaxial Shear Test, Unconfined Compression Test
  • Equipment: Direct Shear Testing Machine, Triaxial Testing Machine, Unconfined Compression Testing Machine
  • Considerations: Shear box size (for direct shear), cell pressure and back pressure control (for triaxial), loading rate control, data acquisition, standards compliance (ASTM D3080 for direct shear, ASTM D4767 for triaxial, ASTM D2166 for unconfined compression).

• Consolidation:

  • Test: Consolidation Test (Oedometer Test)
  • Equipment: Consolidation Testing Machine (Oedometer), Loading Frame, Dial Gauges or LVDTs
  • Considerations: Loading system (dead weights or pneumatic/hydraulic), sample size, data acquisition, standards compliance (ASTM D2435).

• Permeability (Hydraulic Conductivity):

  • Tests: Constant Head Permeability Test, Falling Head Permeability Test
  • Equipment: Permeameter, Constant Head Reservoir, Graduated Cylinder, Stopwatch
  • Considerations: Permeameter type, sample size, head measurement accuracy, standards compliance (ASTM D2434).

• Compaction:

  • Tests: Standard Proctor Test, Modified Proctor Test
  • Equipment: Proctor Mold, Compaction Hammer (standard or modified), Graduated Cylinder, Drying Oven, Balance
  • Considerations: Mold size, hammer weight and drop height, standards compliance (ASTM D698 for standard Proctor, ASTM D1557 for modified Proctor).

• California Bearing Ratio (CBR):

  • Test: CBR Test
  • Equipment: CBR Testing Machine, CBR Mold, Penetration Piston
  • Considerations: Machine capacity, penetration rate, standards compliance (ASTM D1883, AASHTO T193).

• Field Testing Equipment:

• Nuclear Density Gauge: For rapid determination of soil density and moisture content in the field.
• Dynamic Cone Penetrometer (DCP): For evaluating soil strength and bearing capacity in situ.
• Field Permeameters: For measuring permeability in the field.